Improvement in expanding reamers



R. BLAIR.

EXPANDING REAMER.

PatentedJune 5,1877.

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momma WITNESSES;

UNITED STATES PATENT OFFIcn ROBERT BLAIR, OF SAN FRANCISCO, OALIFORN IA.

IMPROVEMENT IN EXPANDING REAMERS.

Specification forming part of Letters Patent No. 19!,568 dated June 5, 1877; application filed April 4, 1876.

Figure 1 is a plan of my improved tool,

vthe clamping-bolt by which the cutters are 'clamped fast after being adjusted being shown in section. Fig. 2 is a section of the tool, taken on the line a: as. Fig. 3 is a section on the line y 3 Similar letters of reference indicate correspondin g parts.

A is the stock, and B the cutters. ,The latter are arranged to slide directly across the stock in dovetail grooves O, and are slotted at E to slide along the clamping-bolt F and washers M, by which they are clamped fast after they are adjusted to the position required by the toothed pinion J and racks G.

The pinion J is arranged in the stock between the cutters, and the shaft extends out of the end of the stock, with a nick in the end for a screw-driver to turn it.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The combination of the sliding cutters B, having rack-arms G and slots E, clampingbolt F, pinion J, and shaft H, with the stock A, having dovetail grooves, as and for the purpose set forth. 7

ROBERT BLAIR.

Witnesses:

JAMES BLAIR, JOHN ARGALL. 

